<?php

/**
 * CActiveRecord class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright 2008-2013 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CActiveRecord is the base class for classes representing relational data.
 *
 * It implements the active record design pattern, a popular Object-Relational Mapping (ORM) technique.
 * Please check {@link http://www.yiiframework.com/doc/guide/database.ar the Guide} for more details
 * about this class.
 *
 * @property CDbCriteria $dbCriteria The query criteria that is associated with this model.
 * This criteria is mainly used by {@link scopes named scope} feature to accumulate
 * different criteria specifications.
 * @property CActiveRecordMetaData $metaData The meta for this AR class.
 * @property CDbConnection $dbConnection The database connection used by active record.
 * @property CDbTableSchema $tableSchema The metadata of the table that this AR belongs to.
 * @property CDbCommandBuilder $commandBuilder The command builder used by this AR.
 * @property array $attributes Attribute values indexed by attribute names.
 * @property boolean $isNewRecord Whether the record is new and should be inserted when calling {@link save}.
 * This property is automatically set in constructor and {@link populateRecord}.
 * Defaults to false, but it will be set to true if the instance is created using
 * the new operator.
 * @property mixed $primaryKey The primary key value. An array (column name=>column value) is returned if the primary key is composite.
 * If primary key is not defined, null will be returned.
 * @property mixed $oldPrimaryKey The old primary key value. An array (column name=>column value) is returned if the primary key is composite.
 * If primary key is not defined, null will be returned.
 * @property string $tableAlias The default table alias.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 * @since 1.0
 */
abstract class CActiveRecord extends CModel
{

    const BELONGS_TO = 'CBelongsToRelation';
    const HAS_ONE = 'CHasOneRelation';
    const HAS_MANY = 'CHasManyRelation';
    const MANY_MANY = 'CManyManyRelation';
    const STAT = 'CStatRelation';

    /**
     * @var CDbConnection the default database connection for all active record classes.
     * By default, this is the 'db' application component.
     * @see getDbConnection
     */
    public static $db;
    private static $_models = array();   // class name => model
    private static $_md = array();    // class name => meta data
    private $_new = false;      // whether this instance is new or not
    private $_attributes = array();    // attribute name => attribute value
    private $_related = array();     // attribute name => related objects
    private $_c;        // query criteria (used by finder only)
    private $_pk;        // old primary key value
    private $_alias = 't';      // the table alias being used for query

    /**
     * Constructor.
     * @param string $scenario scenario name. See {@link CModel::scenario} for more details about this parameter.
     * Note: in order to setup initial model parameters use {@link init()} or {@link afterConstruct()}.
     * Do NOT override the constructor unless it is absolutely necessary!
     */

    public function __construct($scenario = 'insert')
    {
        if ($scenario === null) // internally used by populateRecord() and model()
            return;

        $this->setScenario($scenario);
        $this->setIsNewRecord(true);
        $this->_attributes = $this->getMetaData()->attributeDefaults;

        $this->init();

        $this->attachBehaviors($this->behaviors());
        $this->afterConstruct();
    }

    /**
     * Initializes this model.
     * This method is invoked when an AR instance is newly created and has
     * its {@link scenario} set.
     * You may override this method to provide code that is needed to initialize the model (e.g. setting
     * initial property values.)
     */
    public function init()
    {
        
    }

    /**
     * Sets the parameters about query caching.
     * This is a shortcut method to {@link CDbConnection::cache()}.
     * It changes the query caching parameter of the {@link dbConnection} instance.
     * @param integer $duration the number of seconds that query results may remain valid in cache.
     * If this is 0, the caching will be disabled.
     * @param CCacheDependency|ICacheDependency $dependency the dependency that will be used when saving
     * the query results into cache.
     * @param integer $queryCount number of SQL queries that need to be cached after calling this method. Defaults to 1,
     * meaning that the next SQL query will be cached.
     * @return CActiveRecord the active record instance itself.
     * @since 1.1.7
     */
    public function cache($duration, $dependency = null, $queryCount = 1)
    {
        $this->getDbConnection()->cache($duration, $dependency, $queryCount);
        return $this;
    }

    /**
     * PHP sleep magic method.
     * This method ensures that the model meta data reference is set to null.
     * @return array
     */
    public function __sleep()
    {
        return array_keys((array) $this);
    }

    /**
     * PHP getter magic method.
     * This method is overridden so that AR attributes can be accessed like properties.
     * @param string $name property name
     * @return mixed property value
     * @see getAttribute
     */
    public function __get($name)
    {
        if (isset($this->_attributes[$name]))
            return $this->_attributes[$name];
        elseif (isset($this->getMetaData()->columns[$name]))
            return null;
        elseif (isset($this->_related[$name]))
            return $this->_related[$name];
        elseif (isset($this->getMetaData()->relations[$name]))
            return $this->getRelated($name);
        else
            return parent::__get($name);
    }

    /**
     * PHP setter magic method.
     * This method is overridden so that AR attributes can be accessed like properties.
     * @param string $name property name
     * @param mixed $value property value
     */
    public function __set($name, $value)
    {
        if ($this->setAttribute($name, $value) === false) {
            if (isset($this->getMetaData()->relations[$name]))
                $this->_related[$name] = $value;
            else
                parent::__set($name, $value);
        }
    }

    /**
     * Checks if a property value is null.
     * This method overrides the parent implementation by checking
     * if the named attribute is null or not.
     * @param string $name the property name or the event name
     * @return boolean whether the property value is null
     */
    public function __isset($name)
    {
        if (isset($this->_attributes[$name]))
            return true;
        elseif (isset($this->getMetaData()->columns[$name]))
            return false;
        elseif (isset($this->_related[$name]))
            return true;
        elseif (isset($this->getMetaData()->relations[$name]))
            return $this->getRelated($name) !== null;
        else
            return parent::__isset($name);
    }

    /**
     * Sets a component property to be null.
     * This method overrides the parent implementation by clearing
     * the specified attribute value.
     * @param string $name the property name or the event name
     */
    public function __unset($name)
    {
        if (isset($this->getMetaData()->columns[$name]))
            unset($this->_attributes[$name]);
        elseif (isset($this->getMetaData()->relations[$name]))
            unset($this->_related[$name]);
        else
            parent::__unset($name);
    }

    /**
     * Calls the named method which is not a class method.
     * Do not call this method. This is a PHP magic method that we override
     * to implement the named scope feature.
     * @param string $name the method name
     * @param array $parameters method parameters
     * @return mixed the method return value
     */
    public function __call($name, $parameters)
    {
        if (isset($this->getMetaData()->relations[$name])) {
            if (empty($parameters))
                return $this->getRelated($name, false);
            else
                return $this->getRelated($name, false, $parameters[0]);
        }

        $scopes = $this->scopes();
        if (isset($scopes[$name])) {
            $this->getDbCriteria()->mergeWith($scopes[$name]);
            return $this;
        }

        return parent::__call($name, $parameters);
    }

    /**
     * Returns the related record(s).
     * This method will return the related record(s) of the current record.
     * If the relation is HAS_ONE or BELONGS_TO, it will return a single object
     * or null if the object does not exist.
     * If the relation is HAS_MANY or MANY_MANY, it will return an array of objects
     * or an empty array.
     * @param string $name the relation name (see {@link relations})
     * @param boolean $refresh whether to reload the related objects from database. Defaults to false.
     * If the current record is not a new record and it does not have the related objects loaded they
     * will be retrieved from the database even if this is set to false.
     * If the current record is a new record and this value is false, the related objects will not be
     * retrieved from the database.
     * @param mixed $params array or CDbCriteria object with additional parameters that customize the query conditions as specified in the relation declaration.
     * If this is supplied the related record(s) will be retrieved from the database regardless of the value or {@link $refresh}.
     * The related record(s) retrieved when this is supplied will only be returned by this method and will not be loaded into the current record's relation.
     * The value of the relation prior to running this method will still be available for the current record if this is supplied.
     * @return mixed the related object(s).
     * @throws CDbException if the relation is not specified in {@link relations}.
     */
    public function getRelated($name, $refresh = false, $params = array())
    {
        if (!$refresh && $params === array() && (isset($this->_related[$name]) || array_key_exists($name, $this->_related)))
            return $this->_related[$name];

        $md = $this->getMetaData();
        if (!isset($md->relations[$name]))
            throw new CDbException(Yii::t('yii', '{class} does not have relation "{name}".', array('{class}' => get_class($this), '{name}' => $name)));

        Yii::trace('lazy loading ' . get_class($this) . '.' . $name, 'system.db.ar.CActiveRecord');
        $relation = $md->relations[$name];
        if ($this->getIsNewRecord() && !$refresh && ($relation instanceof CHasOneRelation || $relation instanceof CHasManyRelation))
            return $relation instanceof CHasOneRelation ? null : array();

        if ($params !== array()) { // dynamic query
            $exists = isset($this->_related[$name]) || array_key_exists($name, $this->_related);
            if ($exists)
                $save = $this->_related[$name];

            if ($params instanceof CDbCriteria)
                $params = $params->toArray();

            $r = array($name => $params);
        } else
            $r = $name;
        unset($this->_related[$name]);

        $finder = $this->getActiveFinder($r);
        $finder->lazyFind($this);

        if (!isset($this->_related[$name])) {
            if ($relation instanceof CHasManyRelation)
                $this->_related[$name] = array();
            elseif ($relation instanceof CStatRelation)
                $this->_related[$name] = $relation->defaultValue;
            else
                $this->_related[$name] = null;
        }

        if ($params !== array()) {
            $results = $this->_related[$name];
            if ($exists)
                $this->_related[$name] = $save;
            else
                unset($this->_related[$name]);
            return $results;
        } else
            return $this->_related[$name];
    }

    /**
     * Returns a value indicating whether the named related object(s) has been loaded.
     * @param string $name the relation name
     * @return boolean a value indicating whether the named related object(s) has been loaded.
     */
    public function hasRelated($name)
    {
        return isset($this->_related[$name]) || array_key_exists($name, $this->_related);
    }

    /**
     * Returns the query criteria associated with this model.
     * @param boolean $createIfNull whether to create a criteria instance if it does not exist. Defaults to true.
     * @return CDbCriteria the query criteria that is associated with this model.
     * This criteria is mainly used by {@link scopes named scope} feature to accumulate
     * different criteria specifications.
     */
    public function getDbCriteria($createIfNull = true)
    {
        if ($this->_c === null) {
            if (($c = $this->defaultScope()) !== array() || $createIfNull)
                $this->_c = new CDbCriteria($c);
        }
        return $this->_c;
    }

    /**
     * Sets the query criteria for the current model.
     * @param CDbCriteria $criteria the query criteria
     * @since 1.1.3
     */
    public function setDbCriteria($criteria)
    {
        $this->_c = $criteria;
    }

    /**
     * Returns the default named scope that should be implicitly applied to all queries for this model.
     * Note, default scope only applies to SELECT queries. It is ignored for INSERT, UPDATE and DELETE queries.
     * The default implementation simply returns an empty array. You may override this method
     * if the model needs to be queried with some default criteria (e.g. only active records should be returned).
     * @return array the query criteria. This will be used as the parameter to the constructor
     * of {@link CDbCriteria}.
     */
    public function defaultScope()
    {
        return array();
    }

    /**
     * Resets all scopes and criterias applied.
     *
     * @param boolean $resetDefault including default scope. This parameter available since 1.1.12
     * @return CActiveRecord
     * @since 1.1.2
     */
    public function resetScope($resetDefault = true)
    {
        if ($resetDefault)
            $this->_c = new CDbCriteria();
        else
            $this->_c = null;

        return $this;
    }

    /**
     * Returns the static model of the specified AR class.
     * The model returned is a static instance of the AR class.
     * It is provided for invoking class-level methods (something similar to static class methods.)
     *
     * EVERY derived AR class must override this method as follows,
     * <pre>
     * public static function model($className=__CLASS__)
     * {
     *     return parent::model($className);
     * }
     * </pre>
     *
     * @param string $className active record class name.
     * @return CActiveRecord active record model instance.
     */
    public static function model($className = __CLASS__)
    {
        if (isset(self::$_models[$className]))
            return self::$_models[$className];
        else {
            $model = self::$_models[$className] = new $className(null);
            $model->attachBehaviors($model->behaviors());
            return $model;
        }
    }

    /**
     * Returns the meta-data for this AR
     * @return CActiveRecordMetaData the meta for this AR class.
     */
    public function getMetaData()
    {
        $className = get_class($this);
        if (!array_key_exists($className, self::$_md)) {
            self::$_md[$className] = null; // preventing recursive invokes of {@link getMetaData()} via {@link __get()}
            self::$_md[$className] = new CActiveRecordMetaData($this);
        }
        return self::$_md[$className];
    }

    /**
     * Refreshes the meta data for this AR class.
     * By calling this method, this AR class will regenerate the meta data needed.
     * This is useful if the table schema has been changed and you want to use the latest
     * available table schema. Make sure you have called {@link CDbSchema::refresh}
     * before you call this method. Otherwise, old table schema data will still be used.
     */
    public function refreshMetaData()
    {
        $className = get_class($this);
        if (array_key_exists($className, self::$_md))
            unset(self::$_md[$className]);
    }

    /**
     * Returns the name of the associated database table.
     * By default this method returns the class name as the table name.
     * You may override this method if the table is not named after this convention.
     * @return string the table name
     */
    public function tableName()
    {
        return get_class($this);
    }

    /**
     * Returns the primary key of the associated database table.
     * This method is meant to be overridden in case when the table is not defined with a primary key
     * (for some legency database). If the table is already defined with a primary key,
     * you do not need to override this method. The default implementation simply returns null,
     * meaning using the primary key defined in the database.
     * @return mixed the primary key of the associated database table.
     * If the key is a single column, it should return the column name;
     * If the key is a composite one consisting of several columns, it should
     * return the array of the key column names.
     */
    public function primaryKey()
    {
        
    }

    /**
     * This method should be overridden to declare related objects.
     *
     * There are four types of relations that may exist between two active record objects:
     * <ul>
     * <li>BELONGS_TO: e.g. a member belongs to a team;</li>
     * <li>HAS_ONE: e.g. a member has at most one profile;</li>
     * <li>HAS_MANY: e.g. a team has many members;</li>
     * <li>MANY_MANY: e.g. a member has many skills and a skill belongs to a member.</li>
     * </ul>
     *
     * Besides the above relation types, a special relation called STAT is also supported
     * that can be used to perform statistical query (or aggregational query).
     * It retrieves the aggregational information about the related objects, such as the number
     * of comments for each post, the average rating for each product, etc.
     *
     * Each kind of related objects is defined in this method as an array with the following elements:
     * <pre>
     * 'varName'=>array('relationType', 'className', 'foreignKey', ...additional options)
     * </pre>
     * where 'varName' refers to the name of the variable/property that the related object(s) can
     * be accessed through; 'relationType' refers to the type of the relation, which can be one of the
     * following four constants: self::BELONGS_TO, self::HAS_ONE, self::HAS_MANY and self::MANY_MANY;
     * 'className' refers to the name of the active record class that the related object(s) is of;
     * and 'foreignKey' states the foreign key that relates the two kinds of active record.
     * Note, for composite foreign keys, they can be either listed together, separated by commas or specified as an array
     * in format of array('key1','key2'). In case you need to specify custom PK->FK association you can define it as
     * array('fk'=>'pk'). For composite keys it will be array('fk_c1'=>'pk_с1','fk_c2'=>'pk_c2').
     * For foreign keys used in MANY_MANY relation, the joining table must be declared as well
     * (e.g. 'join_table(fk1, fk2)').
     *
     * Additional options may be specified as name-value pairs in the rest array elements:
     * <ul>
     * <li>'select': string|array, a list of columns to be selected. Defaults to '*', meaning all columns.
     *   Column names should be disambiguated if they appear in an expression (e.g. COUNT(relationName.name) AS name_count).</li>
     * <li>'condition': string, the WHERE clause. Defaults to empty. Note, column references need to
     *   be disambiguated with prefix 'relationName.' (e.g. relationName.age&gt;20)</li>
     * <li>'order': string, the ORDER BY clause. Defaults to empty. Note, column references need to
     *   be disambiguated with prefix 'relationName.' (e.g. relationName.age DESC)</li>
     * <li>'with': string|array, a list of child related objects that should be loaded together with this object.
     *   Note, this is only honored by lazy loading, not eager loading.</li>
     * <li>'joinType': type of join. Defaults to 'LEFT OUTER JOIN'.</li>
     * <li>'alias': the alias for the table associated with this relationship.
     *   It defaults to null,
     *   meaning the table alias is the same as the relation name.</li>
     * <li>'params': the parameters to be bound to the generated SQL statement.
     *   This should be given as an array of name-value pairs.</li>
     * <li>'on': the ON clause. The condition specified here will be appended
     *   to the joining condition using the AND operator.</li>
     * <li>'index': the name of the column whose values should be used as keys
     *   of the array that stores related objects. This option is only available to
     *   HAS_MANY and MANY_MANY relations.</li>
     * <li>'scopes': scopes to apply. In case of a single scope can be used like 'scopes'=>'scopeName',
     *   in case of multiple scopes can be used like 'scopes'=>array('scopeName1','scopeName2').
     *   This option has been available since version 1.1.9.</li>
     * </ul>
     *
     * The following options are available for certain relations when lazy loading:
     * <ul>
     * <li>'group': string, the GROUP BY clause. Defaults to empty. Note, column references need to
     *   be disambiguated with prefix 'relationName.' (e.g. relationName.age). This option only applies to HAS_MANY and MANY_MANY relations.</li>
     * <li>'having': string, the HAVING clause. Defaults to empty. Note, column references need to
     *   be disambiguated with prefix 'relationName.' (e.g. relationName.age). This option only applies to HAS_MANY and MANY_MANY relations.</li>
     * <li>'limit': limit of the rows to be selected. This option does not apply to BELONGS_TO relation.</li>
     * <li>'offset': offset of the rows to be selected. This option does not apply to BELONGS_TO relation.</li>
     * <li>'through': name of the model's relation that will be used as a bridge when getting related data. Can be set only for HAS_ONE and HAS_MANY. This option has been available since version 1.1.7.</li>
     * </ul>
     *
     * Below is an example declaring related objects for 'Post' active record class:
     * <pre>
     * return array(
     *     'author'=>array(self::BELONGS_TO, 'User', 'author_id'),
     *     'comments'=>array(self::HAS_MANY, 'Comment', 'post_id', 'with'=>'author', 'order'=>'create_time DESC'),
     *     'tags'=>array(self::MANY_MANY, 'Tag', 'post_tag(post_id, tag_id)', 'order'=>'name'),
     * );
     * </pre>
     *
     * @return array list of related object declarations. Defaults to empty array.
     */
    public function relations()
    {
        return array();
    }

    /**
     * Returns the declaration of named scopes.
     * A named scope represents a query criteria that can be chained together with
     * other named scopes and applied to a query. This method should be overridden
     * by child classes to declare named scopes for the particular AR classes.
     * For example, the following code declares two named scopes: 'recently' and
     * 'published'.
     * <pre>
     * return array(
     *     'published'=>array(
     *           'condition'=>'status=1',
     *     ),
     *     'recently'=>array(
     *           'order'=>'create_time DESC',
     *           'limit'=>5,
     *     ),
     * );
     * </pre>
     * If the above scopes are declared in a 'Post' model, we can perform the following
     * queries:
     * <pre>
     * $posts=Post::model()->published()->findAll();
     * $posts=Post::model()->published()->recently()->findAll();
     * $posts=Post::model()->published()->with('comments')->findAll();
     * </pre>
     * Note that the last query is a relational query.
     *
     * @return array the scope definition. The array keys are scope names; the array
     * values are the corresponding scope definitions. Each scope definition is represented
     * as an array whose keys must be properties of {@link CDbCriteria}.
     */
    public function scopes()
    {
        return array();
    }

    /**
     * Returns the list of all attribute names of the model.
     * This would return all column names of the table associated with this AR class.
     * @return array list of attribute names.
     */
    public function attributeNames()
    {
        return array_keys($this->getMetaData()->columns);
    }

    /**
     * Returns the text label for the specified attribute.
     * This method overrides the parent implementation by supporting
     * returning the label defined in relational object.
     * In particular, if the attribute name is in the form of "post.author.name",
     * then this method will derive the label from the "author" relation's "name" attribute.
     * @param string $attribute the attribute name
     * @return string the attribute label
     * @see generateAttributeLabel
     * @since 1.1.4
     */
    public function getAttributeLabel($attribute)
    {
        $labels = $this->attributeLabels();
        if (isset($labels[$attribute]))
            return $labels[$attribute];
        elseif (strpos($attribute, '.') !== false) {
            $segs = explode('.', $attribute);
            $name = array_pop($segs);
            $model = $this;
            foreach ($segs as $seg) {
                $relations = $model->getMetaData()->relations;
                if (isset($relations[$seg]))
                    $model = CActiveRecord::model($relations[$seg]->className);
                else
                    break;
            }
            return $model->getAttributeLabel($name);
        } else
            return $this->generateAttributeLabel($attribute);
    }

    /**
     * Returns the database connection used by active record.
     * By default, the "db" application component is used as the database connection.
     * You may override this method if you want to use a different database connection.
     * @throws CDbException if "db" application component is not defined
     * @return CDbConnection the database connection used by active record.
     */
    public function getDbConnection()
    {
        if (self::$db !== null)
            return self::$db;
        else {
            self::$db = Yii::app()->getDb();
            if (self::$db instanceof CDbConnection)
                return self::$db;
            else
                throw new CDbException(Yii::t('yii', 'Active Record requires a "db" CDbConnection application component.'));
        }
    }

    /**
     * Returns the named relation declared for this AR class.
     * @param string $name the relation name
     * @return CActiveRelation the named relation declared for this AR class. Null if the relation does not exist.
     */
    public function getActiveRelation($name)
    {
        return isset($this->getMetaData()->relations[$name]) ? $this->getMetaData()->relations[$name] : null;
    }

    /**
     * Returns the metadata of the table that this AR belongs to
     * @return CDbTableSchema the metadata of the table that this AR belongs to
     */
    public function getTableSchema()
    {
        return $this->getMetaData()->tableSchema;
    }

    /**
     * Returns the command builder used by this AR.
     * @return CDbCommandBuilder the command builder used by this AR
     */
    public function getCommandBuilder()
    {
        return $this->getDbConnection()->getSchema()->getCommandBuilder();
    }

    /**
     * Checks whether this AR has the named attribute
     * @param string $name attribute name
     * @return boolean whether this AR has the named attribute (table column).
     */
    public function hasAttribute($name)
    {
        return isset($this->getMetaData()->columns[$name]);
    }

    /**
     * Returns the named attribute value.
     * If this is a new record and the attribute is not set before,
     * the default column value will be returned.
     * If this record is the result of a query and the attribute is not loaded,
     * null will be returned.
     * You may also use $this->AttributeName to obtain the attribute value.
     * @param string $name the attribute name
     * @return mixed the attribute value. Null if the attribute is not set or does not exist.
     * @see hasAttribute
     */
    public function getAttribute($name)
    {
        if (property_exists($this, $name))
            return $this->$name;
        elseif (isset($this->_attributes[$name]))
            return $this->_attributes[$name];
    }

    /**
     * Sets the named attribute value.
     * You may also use $this->AttributeName to set the attribute value.
     * @param string $name the attribute name
     * @param mixed $value the attribute value.
     * @return boolean whether the attribute exists and the assignment is conducted successfully
     * @see hasAttribute
     */
    public function setAttribute($name, $value)
    {
        if (property_exists($this, $name))
            $this->$name = $value;
        elseif (isset($this->getMetaData()->columns[$name]))
            $this->_attributes[$name] = $value;
        else
            return false;
        return true;
    }

    /**
     * Do not call this method. This method is used internally by {@link CActiveFinder} to populate
     * related objects. This method adds a related object to this record.
     * @param string $name attribute name
     * @param mixed $record the related record
     * @param mixed $index the index value in the related object collection.
     * If true, it means using zero-based integer index.
     * If false, it means a HAS_ONE or BELONGS_TO object and no index is needed.
     */
    public function addRelatedRecord($name, $record, $index)
    {
        if ($index !== false) {
            if (!isset($this->_related[$name]))
                $this->_related[$name] = array();
            if ($record instanceof CActiveRecord) {
                if ($index === true)
                    $this->_related[$name][] = $record;
                else
                    $this->_related[$name][$index] = $record;
            }
        }
        elseif (!isset($this->_related[$name]))
            $this->_related[$name] = $record;
    }

    /**
     * Returns all column attribute values.
     * Note, related objects are not returned.
     * @param mixed $names names of attributes whose value needs to be returned.
     * If this is true (default), then all attribute values will be returned, including
     * those that are not loaded from DB (null will be returned for those attributes).
     * If this is null, all attributes except those that are not loaded from DB will be returned.
     * @return array attribute values indexed by attribute names.
     */
    public function getAttributes($names = true)
    {
        $attributes = $this->_attributes;
        foreach ($this->getMetaData()->columns as $name => $column) {
            if (property_exists($this, $name))
                $attributes[$name] = $this->$name;
            elseif ($names === true && !isset($attributes[$name]))
                $attributes[$name] = null;
        }
        if (is_array($names)) {
            $attrs = array();
            foreach ($names as $name) {
                if (property_exists($this, $name))
                    $attrs[$name] = $this->$name;
                else
                    $attrs[$name] = isset($attributes[$name]) ? $attributes[$name] : null;
            }
            return $attrs;
        } else
            return $attributes;
    }

    /**
     * Saves the current record.
     *
     * The record is inserted as a row into the database table if its {@link isNewRecord}
     * property is true (usually the case when the record is created using the 'new'
     * operator). Otherwise, it will be used to update the corresponding row in the table
     * (usually the case if the record is obtained using one of those 'find' methods.)
     *
     * Validation will be performed before saving the record. If the validation fails,
     * the record will not be saved. You can call {@link getErrors()} to retrieve the
     * validation errors.
     *
     * If the record is saved via insertion, its {@link isNewRecord} property will be
     * set false, and its {@link scenario} property will be set to be 'update'.
     * And if its primary key is auto-incremental and is not set before insertion,
     * the primary key will be populated with the automatically generated key value.
     *
     * @param boolean $runValidation whether to perform validation before saving the record.
     * If the validation fails, the record will not be saved to database.
     * @param array $attributes list of attributes that need to be saved. Defaults to null,
     * meaning all attributes that are loaded from DB will be saved.
     * @return boolean whether the saving succeeds
     */
    public function save($runValidation = true, $attributes = null)
    {
        if (!$runValidation || $this->validate($attributes))
            return $this->getIsNewRecord() ? $this->insert($attributes) : $this->update($attributes);
        else
            return false;
    }

    /**
     * Returns if the current record is new.
     * @return boolean whether the record is new and should be inserted when calling {@link save}.
     * This property is automatically set in constructor and {@link populateRecord}.
     * Defaults to false, but it will be set to true if the instance is created using
     * the new operator.
     */
    public function getIsNewRecord()
    {
        return $this->_new;
    }

    /**
     * Sets if the record is new.
     * @param boolean $value whether the record is new and should be inserted when calling {@link save}.
     * @see getIsNewRecord
     */
    public function setIsNewRecord($value)
    {
        $this->_new = $value;
    }

    /**
     * This event is raised before the record is saved.
     * By setting {@link CModelEvent::isValid} to be false, the normal {@link save()} process will be stopped.
     * @param CModelEvent $event the event parameter
     */
    public function onBeforeSave($event)
    {
        $this->raiseEvent('onBeforeSave', $event);
    }

    /**
     * This event is raised after the record is saved.
     * @param CEvent $event the event parameter
     */
    public function onAfterSave($event)
    {
        $this->raiseEvent('onAfterSave', $event);
    }

    /**
     * This event is raised before the record is deleted.
     * By setting {@link CModelEvent::isValid} to be false, the normal {@link delete()} process will be stopped.
     * @param CModelEvent $event the event parameter
     */
    public function onBeforeDelete($event)
    {
        $this->raiseEvent('onBeforeDelete', $event);
    }

    /**
     * This event is raised after the record is deleted.
     * @param CEvent $event the event parameter
     */
    public function onAfterDelete($event)
    {
        $this->raiseEvent('onAfterDelete', $event);
    }

    /**
     * This event is raised before an AR finder performs a find call.
     * This can be either a call to CActiveRecords find methods or a find call
     * when model is loaded in relational context via lazy or eager loading.
     * If you want to access or modify the query criteria used for the
     * find call, you can use {@link getDbCriteria()} to customize it based on your needs.
     * When modifying criteria in beforeFind you have to make sure you are using the right
     * table alias which is different on normal find and relational call.
     * You can use {@link getTableAlias()} to get the alias used for the upcoming find call.
     * Please note that modification of criteria is fully supported as of version 1.1.13.
     * Earlier versions had some problems with relational context and applying changes correctly.
     * @param CModelEvent $event the event parameter
     * @see beforeFind
     */
    public function onBeforeFind($event)
    {
        $this->raiseEvent('onBeforeFind', $event);
    }

    /**
     * This event is raised after the record is instantiated by a find method.
     * @param CEvent $event the event parameter
     */
    public function onAfterFind($event)
    {
        $this->raiseEvent('onAfterFind', $event);
    }

    /**
     * Given 'with' options returns a new active finder instance.
     *
     * @param mixed $with the relation names to be actively looked for
     * @return CActiveFinder active finder for the operation
     *
     * @since 1.1.14
     */
    public function getActiveFinder($with)
    {
        return new CActiveFinder($this, $with);
    }

    /**
     * This event is raised before an AR finder performs a count call.
     * If you want to access or modify the query criteria used for the
     * count call, you can use {@link getDbCriteria()} to customize it based on your needs.
     * When modifying criteria in beforeCount you have to make sure you are using the right
     * table alias which is different on normal count and relational call.
     * You can use {@link getTableAlias()} to get the alias used for the upcoming count call.
     * @param CModelEvent $event the event parameter
     * @see beforeCount
     * @since 1.1.14
     */
    public function onBeforeCount($event)
    {
        $this->raiseEvent('onBeforeCount', $event);
    }

    /**
     * This method is invoked before saving a record (after validation, if any).
     * The default implementation raises the {@link onBeforeSave} event.
     * You may override this method to do any preparation work for record saving.
     * Use {@link isNewRecord} to determine whether the saving is
     * for inserting or updating record.
     * Make sure you call the parent implementation so that the event is raised properly.
     * @return boolean whether the saving should be executed. Defaults to true.
     */
    protected function beforeSave()
    {
        if ($this->hasEventHandler('onBeforeSave')) {
            $event = new CModelEvent($this);
            $this->onBeforeSave($event);
            return $event->isValid;
        } else
            return true;
    }

    /**
     * This method is invoked after saving a record successfully.
     * The default implementation raises the {@link onAfterSave} event.
     * You may override this method to do postprocessing after record saving.
     * Make sure you call the parent implementation so that the event is raised properly.
     */
    protected function afterSave()
    {
        if ($this->hasEventHandler('onAfterSave'))
            $this->onAfterSave(new CEvent($this));
    }

    /**
     * This method is invoked before deleting a record.
     * The default implementation raises the {@link onBeforeDelete} event.
     * You may override this method to do any preparation work for record deletion.
     * Make sure you call the parent implementation so that the event is raised properly.
     * @return boolean whether the record should be deleted. Defaults to true.
     */
    protected function beforeDelete()
    {
        if ($this->hasEventHandler('onBeforeDelete')) {
            $event = new CModelEvent($this);
            $this->onBeforeDelete($event);
            return $event->isValid;
        } else
            return true;
    }

    /**
     * This method is invoked after deleting a record.
     * The default implementation raises the {@link onAfterDelete} event.
     * You may override this method to do postprocessing after the record is deleted.
     * Make sure you call the parent implementation so that the event is raised properly.
     */
    protected function afterDelete()
    {
        if ($this->hasEventHandler('onAfterDelete'))
            $this->onAfterDelete(new CEvent($this));
    }

    /**
     * This method is invoked before an AR finder executes a find call.
     * The find calls include {@link find}, {@link findAll}, {@link findByPk},
     * {@link findAllByPk}, {@link findByAttributes}, {@link findAllByAttributes},
     * {@link findBySql} and {@link findAllBySql}.
     * The default implementation raises the {@link onBeforeFind} event.
     * If you override this method, make sure you call the parent implementation
     * so that the event is raised properly.
     * For details on modifying query criteria see {@link onBeforeFind} event.
     */
    protected function beforeFind()
    {
        if ($this->hasEventHandler('onBeforeFind')) {
            $event = new CModelEvent($this);
            $this->onBeforeFind($event);
        }
    }

    /**
     * This method is invoked before an AR finder executes a count call.
     * The count calls include {@link count} and {@link countByAttributes}
     * The default implementation raises the {@link onBeforeCount} event.
     * If you override this method, make sure you call the parent implementation
     * so that the event is raised properly.
     * @since 1.1.14
     */
    protected function beforeCount()
    {
        if ($this->hasEventHandler('onBeforeCount'))
            $this->onBeforeCount(new CEvent($this));
    }

    /**
     * This method is invoked after each record is instantiated by a find method.
     * The default implementation raises the {@link onAfterFind} event.
     * You may override this method to do postprocessing after each newly found record is instantiated.
     * Make sure you call the parent implementation so that the event is raised properly.
     */
    protected function afterFind()
    {
        if ($this->hasEventHandler('onAfterFind'))
            $this->onAfterFind(new CEvent($this));
    }

    /**
     * Calls {@link beforeFind}.
     * This method is internally used.
     */
    public function beforeFindInternal()
    {
        $this->beforeFind();
    }

    /**
     * Calls {@link afterFind}.
     * This method is internally used.
     */
    public function afterFindInternal()
    {
        $this->afterFind();
    }

    /**
     * Inserts a row into the table based on this active record attributes.
     * If the table's primary key is auto-incremental and is null before insertion,
     * it will be populated with the actual value after insertion.
     * Note, validation is not performed in this method. You may call {@link validate} to perform the validation.
     * After the record is inserted to DB successfully, its {@link isNewRecord} property will be set false,
     * and its {@link scenario} property will be set to be 'update'.
     * @param array $attributes list of attributes that need to be saved. Defaults to null,
     * meaning all attributes that are loaded from DB will be saved.
     * @return boolean whether the attributes are valid and the record is inserted successfully.
     * @throws CDbException if the record is not new
     */
    public function insert($attributes = null)
    {
        if (!$this->getIsNewRecord())
            throw new CDbException(Yii::t('yii', 'The active record cannot be inserted to database because it is not new.'));
        if ($this->beforeSave()) {
            Yii::trace(get_class($this) . '.insert()', 'system.db.ar.CActiveRecord');
            $builder = $this->getCommandBuilder();
            $table = $this->getMetaData()->tableSchema;
            $command = $builder->createInsertCommand($table, $this->getAttributes($attributes));
            if ($command->execute()) {
                $primaryKey = $table->primaryKey;
                if ($table->sequenceName !== null) {
                    if (is_string($primaryKey) && $this->$primaryKey === null)
                        $this->$primaryKey = $builder->getLastInsertID($table);
                    elseif (is_array($primaryKey)) {
                        foreach ($primaryKey as $pk) {
                            if ($this->$pk === null) {
                                $this->$pk = $builder->getLastInsertID($table);
                                break;
                            }
                        }
                    }
                }
                $this->_pk = $this->getPrimaryKey();
                $this->afterSave();
                $this->setIsNewRecord(false);
                $this->setScenario('update');
                return true;
            }
        }
        return false;
    }

    /**
     * Updates the row represented by this active record.
     * All loaded attributes will be saved to the database.
     * Note, validation is not performed in this method. You may call {@link validate} to perform the validation.
     * @param array $attributes list of attributes that need to be saved. Defaults to null,
     * meaning all attributes that are loaded from DB will be saved.
     * @return boolean whether the update is successful
     * @throws CDbException if the record is new
     */
    public function update($attributes = null)
    {
        if ($this->getIsNewRecord())
            throw new CDbException(Yii::t('yii', 'The active record cannot be updated because it is new.'));
        if ($this->beforeSave()) {
            Yii::trace(get_class($this) . '.update()', 'system.db.ar.CActiveRecord');
            if ($this->_pk === null)
                $this->_pk = $this->getPrimaryKey();
            $this->updateByPk($this->getOldPrimaryKey(), $this->getAttributes($attributes));
            $this->_pk = $this->getPrimaryKey();
            $this->afterSave();
            return true;
        } else
            return false;
    }

    /**
     * Saves a selected list of attributes.
     * Unlike {@link save}, this method only saves the specified attributes
     * of an existing row dataset and does NOT call either {@link beforeSave} or {@link afterSave}.
     * Also note that this method does neither attribute filtering nor validation.
     * So do not use this method with untrusted data (such as user posted data).
     * You may consider the following alternative if you want to do so:
     * <pre>
     * $postRecord=Post::model()->findByPk($postID);
     * $postRecord->attributes=$_POST['post'];
     * $postRecord->save();
     * </pre>
     * @param array $attributes attributes to be updated. Each element represents an attribute name
     * or an attribute value indexed by its name. If the latter, the record's
     * attribute will be changed accordingly before saving.
     * @throws CDbException if the record is new
     * @return boolean whether the update is successful
     */
    public function saveAttributes($attributes)
    {
        if (!$this->getIsNewRecord()) {
            Yii::trace(get_class($this) . '.saveAttributes()', 'system.db.ar.CActiveRecord');
            $values = array();
            foreach ($attributes as $name => $value) {
                if (is_integer($name))
                    $values[$value] = $this->$value;
                else
                    $values[$name] = $this->$name = $value;
            }
            if ($this->_pk === null)
                $this->_pk = $this->getPrimaryKey();
            if ($this->updateByPk($this->getOldPrimaryKey(), $values) > 0) {
                $this->_pk = $this->getPrimaryKey();
                return true;
            } else
                return false;
        } else
            throw new CDbException(Yii::t('yii', 'The active record cannot be updated because it is new.'));
    }

    /**
     * Saves one or several counter columns for the current AR object.
     * Note that this method differs from {@link updateCounters} in that it only
     * saves the current AR object.
     * An example usage is as follows:
     * <pre>
     * $postRecord=Post::model()->findByPk($postID);
     * $postRecord->saveCounters(array('view_count'=>1));
     * </pre>
     * Use negative values if you want to decrease the counters.
     * @param array $counters the counters to be updated (column name=>increment value)
     * @return boolean whether the saving is successful
     * @see updateCounters
     * @since 1.1.8
     */
    public function saveCounters($counters)
    {
        Yii::trace(get_class($this) . '.saveCounters()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $table = $this->getTableSchema();
        $criteria = $builder->createPkCriteria($table, $this->getOldPrimaryKey());
        $command = $builder->createUpdateCounterCommand($this->getTableSchema(), $counters, $criteria);
        if ($command->execute()) {
            foreach ($counters as $name => $value)
                $this->$name = $this->$name + $value;
            return true;
        } else
            return false;
    }

    /**
     * Deletes the row corresponding to this active record.
     * @throws CDbException if the record is new
     * @return boolean whether the deletion is successful.
     */
    public function delete()
    {
        if (!$this->getIsNewRecord()) {
            Yii::trace(get_class($this) . '.delete()', 'system.db.ar.CActiveRecord');
            if ($this->beforeDelete()) {
                $result = $this->deleteByPk($this->getPrimaryKey()) > 0;
                $this->afterDelete();
                return $result;
            } else
                return false;
        } else
            throw new CDbException(Yii::t('yii', 'The active record cannot be deleted because it is new.'));
    }

    /**
     * Repopulates this active record with the latest data.
     * @return boolean whether the row still exists in the database. If true, the latest data will be populated to this active record.
     */
    public function refresh()
    {
        Yii::trace(get_class($this) . '.refresh()', 'system.db.ar.CActiveRecord');
        if (($record = $this->findByPk($this->getPrimaryKey())) !== null) {
            $this->_attributes = array();
            $this->_related = array();
            foreach ($this->getMetaData()->columns as $name => $column) {
                if (property_exists($this, $name))
                    $this->$name = $record->$name;
                else
                    $this->_attributes[$name] = $record->$name;
            }
            return true;
        } else
            return false;
    }

    /**
     * Compares current active record with another one.
     * The comparison is made by comparing table name and the primary key values of the two active records.
     * @param CActiveRecord $record record to compare to
     * @return boolean whether the two active records refer to the same row in the database table.
     */
    public function equals($record)
    {
        return $this->tableName() === $record->tableName() && $this->getPrimaryKey() === $record->getPrimaryKey();
    }

    /**
     * Returns the primary key value.
     * @return mixed the primary key value. An array (column name=>column value) is returned if the primary key is composite.
     * If primary key is not defined, null will be returned.
     */
    public function getPrimaryKey()
    {
        $table = $this->getMetaData()->tableSchema;
        if (is_string($table->primaryKey))
            return $this->{$table->primaryKey};
        elseif (is_array($table->primaryKey)) {
            $values = array();
            foreach ($table->primaryKey as $name)
                $values[$name] = $this->$name;
            return $values;
        } else
            return null;
    }

    /**
     * Sets the primary key value.
     * After calling this method, the old primary key value can be obtained from {@link oldPrimaryKey}.
     * @param mixed $value the new primary key value. If the primary key is composite, the new value
     * should be provided as an array (column name=>column value).
     * @since 1.1.0
     */
    public function setPrimaryKey($value)
    {
        $this->_pk = $this->getPrimaryKey();
        $table = $this->getMetaData()->tableSchema;
        if (is_string($table->primaryKey))
            $this->{$table->primaryKey} = $value;
        elseif (is_array($table->primaryKey)) {
            foreach ($table->primaryKey as $name)
                $this->$name = $value[$name];
        }
    }

    /**
     * Returns the old primary key value.
     * This refers to the primary key value that is populated into the record
     * after executing a find method (e.g. find(), findAll()).
     * The value remains unchanged even if the primary key attribute is manually assigned with a different value.
     * @return mixed the old primary key value. An array (column name=>column value) is returned if the primary key is composite.
     * If primary key is not defined, null will be returned.
     * @since 1.1.0
     */
    public function getOldPrimaryKey()
    {
        return $this->_pk;
    }

    /**
     * Sets the old primary key value.
     * @param mixed $value the old primary key value.
     * @since 1.1.3
     */
    public function setOldPrimaryKey($value)
    {
        $this->_pk = $value;
    }

    /**
     * Performs the actual DB query and populates the AR objects with the query result.
     * This method is mainly internally used by other AR query methods.
     * @param CDbCriteria $criteria the query criteria
     * @param boolean $all whether to return all data
     * @return mixed the AR objects populated with the query result
     * @since 1.1.7
     */
    protected function query($criteria, $all = false)
    {
        $this->beforeFind();
        $this->applyScopes($criteria);

        if (empty($criteria->with)) {
            if (!$all)
                $criteria->limit = 1;
            $command = $this->getCommandBuilder()->createFindCommand($this->getTableSchema(), $criteria, $this->getTableAlias());
            return $all ? $this->populateRecords($command->queryAll(), true, $criteria->index) : $this->populateRecord($command->queryRow());
        }
        else {
            $finder = $this->getActiveFinder($criteria->with);
            return $finder->query($criteria, $all);
        }
    }

    /**
     * Applies the query scopes to the given criteria.
     * This method merges {@link dbCriteria} with the given criteria parameter.
     * It then resets {@link dbCriteria} to be null.
     * @param CDbCriteria $criteria the query criteria. This parameter may be modified by merging {@link dbCriteria}.
     */
    public function applyScopes(&$criteria)
    {
        if (!empty($criteria->scopes)) {
            $scs = $this->scopes();
            $c = $this->getDbCriteria();
            foreach ((array) $criteria->scopes as $k => $v) {
                if (is_integer($k)) {
                    if (is_string($v)) {
                        if (isset($scs[$v])) {
                            $c->mergeWith($scs[$v], true);
                            continue;
                        }
                        $scope = $v;
                        $params = array();
                    } elseif (is_array($v)) {
                        $scope = key($v);
                        $params = current($v);
                    }
                } elseif (is_string($k)) {
                    $scope = $k;
                    $params = $v;
                }

                call_user_func_array(array($this, $scope), (array) $params);
            }
        }

        if (isset($c) || ($c = $this->getDbCriteria(false)) !== null) {
            $c->mergeWith($criteria);
            $criteria = $c;
            $this->resetScope(false);
        }
    }

    /**
     * Returns the table alias to be used by the find methods.
     * In relational queries, the returned table alias may vary according to
     * the corresponding relation declaration. Also, the default table alias
     * set by {@link setTableAlias} may be overridden by the applied scopes.
     * @param boolean $quote whether to quote the alias name
     * @param boolean $checkScopes whether to check if a table alias is defined in the applied scopes so far.
     * This parameter must be set false when calling this method in {@link defaultScope}.
     * An infinite loop would be formed otherwise.
     * @return string the default table alias
     * @since 1.1.1
     */
    public function getTableAlias($quote = false, $checkScopes = true)
    {
        if ($checkScopes && ($criteria = $this->getDbCriteria(false)) !== null && $criteria->alias != '')
            $alias = $criteria->alias;
        else
            $alias = $this->_alias;
        return $quote ? $this->getDbConnection()->getSchema()->quoteTableName($alias) : $alias;
    }

    /**
     * Sets the table alias to be used in queries.
     * @param string $alias the table alias to be used in queries. The alias should NOT be quoted.
     * @since 1.1.3
     */
    public function setTableAlias($alias)
    {
        $this->_alias = $alias;
    }

    /**
     * Finds a single active record with the specified condition.
     * @param mixed $condition query condition or criteria.
     * If a string, it is treated as query condition (the WHERE clause);
     * If an array, it is treated as the initial values for constructing a {@link CDbCriteria} object;
     * Otherwise, it should be an instance of {@link CDbCriteria}.
     * @param array $params parameters to be bound to an SQL statement.
     * This is only used when the first parameter is a string (query condition).
     * In other cases, please use {@link CDbCriteria::params} to set parameters.
     * @return CActiveRecord the record found. Null if no record is found.
     */
    public function find($condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.find()', 'system.db.ar.CActiveRecord');
        $criteria = $this->getCommandBuilder()->createCriteria($condition, $params);
        return $this->query($criteria);
    }

    /**
     * Finds all active records satisfying the specified condition.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return CActiveRecord[] list of active records satisfying the specified condition. An empty array is returned if none is found.
     */
    public function findAll($condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.findAll()', 'system.db.ar.CActiveRecord');
        $criteria = $this->getCommandBuilder()->createCriteria($condition, $params);
        return $this->query($criteria, true);
    }

    /**
     * Finds a single active record with the specified primary key.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param mixed $pk primary key value(s). Use array for multiple primary keys. For composite key, each key value must be an array (column name=>column value).
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return CActiveRecord the record found. Null if none is found.
     */
    public function findByPk($pk, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.findByPk()', 'system.db.ar.CActiveRecord');
        $prefix = $this->getTableAlias(true) . '.';
        $criteria = $this->getCommandBuilder()->createPkCriteria($this->getTableSchema(), $pk, $condition, $params, $prefix);
        return $this->query($criteria);
    }

    /**
     * Finds all active records with the specified primary keys.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param mixed $pk primary key value(s). Use array for multiple primary keys. For composite key, each key value must be an array (column name=>column value).
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return CActiveRecord[] the records found. An empty array is returned if none is found.
     */
    public function findAllByPk($pk, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.findAllByPk()', 'system.db.ar.CActiveRecord');
        $prefix = $this->getTableAlias(true) . '.';
        $criteria = $this->getCommandBuilder()->createPkCriteria($this->getTableSchema(), $pk, $condition, $params, $prefix);
        return $this->query($criteria, true);
    }

    /**
     * Finds a single active record that has the specified attribute values.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param array $attributes list of attribute values (indexed by attribute names) that the active records should match.
     * An attribute value can be an array which will be used to generate an IN condition.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return CActiveRecord the record found. Null if none is found.
     */
    public function findByAttributes($attributes, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.findByAttributes()', 'system.db.ar.CActiveRecord');
        $prefix = $this->getTableAlias(true) . '.';
        $criteria = $this->getCommandBuilder()->createColumnCriteria($this->getTableSchema(), $attributes, $condition, $params, $prefix);
        return $this->query($criteria);
    }

    /**
     * Finds all active records that have the specified attribute values.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param array $attributes list of attribute values (indexed by attribute names) that the active records should match.
     * An attribute value can be an array which will be used to generate an IN condition.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return CActiveRecord[] the records found. An empty array is returned if none is found.
     */
    public function findAllByAttributes($attributes, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.findAllByAttributes()', 'system.db.ar.CActiveRecord');
        $prefix = $this->getTableAlias(true) . '.';
        $criteria = $this->getCommandBuilder()->createColumnCriteria($this->getTableSchema(), $attributes, $condition, $params, $prefix);
        return $this->query($criteria, true);
    }

    /**
     * Finds a single active record with the specified SQL statement.
     * @param string $sql the SQL statement
     * @param array $params parameters to be bound to the SQL statement
     * @return CActiveRecord the record found. Null if none is found.
     */
    public function findBySql($sql, $params = array())
    {
        Yii::trace(get_class($this) . '.findBySql()', 'system.db.ar.CActiveRecord');
        $this->beforeFind();
        if (($criteria = $this->getDbCriteria(false)) !== null && !empty($criteria->with)) {
            $this->resetScope(false);
            $finder = $this->getActiveFinder($criteria->with);
            return $finder->findBySql($sql, $params);
        } else {
            $command = $this->getCommandBuilder()->createSqlCommand($sql, $params);
            return $this->populateRecord($command->queryRow());
        }
    }

    /**
     * Finds all active records using the specified SQL statement.
     * @param string $sql the SQL statement
     * @param array $params parameters to be bound to the SQL statement
     * @return CActiveRecord[] the records found. An empty array is returned if none is found.
     */
    public function findAllBySql($sql, $params = array())
    {
        Yii::trace(get_class($this) . '.findAllBySql()', 'system.db.ar.CActiveRecord');
        $this->beforeFind();
        if (($criteria = $this->getDbCriteria(false)) !== null && !empty($criteria->with)) {
            $this->resetScope(false);
            $finder = $this->getActiveFinder($criteria->with);
            return $finder->findAllBySql($sql, $params);
        } else {
            $command = $this->getCommandBuilder()->createSqlCommand($sql, $params);
            return $this->populateRecords($command->queryAll());
        }
    }

    /**
     * Finds the number of rows satisfying the specified query condition.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return string the number of rows satisfying the specified query condition. Note: type is string to keep max. precision.
     */
    public function count($condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.count()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $this->beforeCount();
        $criteria = $builder->createCriteria($condition, $params);
        $this->applyScopes($criteria);

        if (empty($criteria->with))
            return $builder->createCountCommand($this->getTableSchema(), $criteria)->queryScalar();
        else {
            $finder = $this->getActiveFinder($criteria->with);
            return $finder->count($criteria);
        }
    }

    /**
     * Finds the number of rows that have the specified attribute values.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param array $attributes list of attribute values (indexed by attribute names) that the active records should match.
     * An attribute value can be an array which will be used to generate an IN condition.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return string the number of rows satisfying the specified query condition. Note: type is string to keep max. precision.
     * @since 1.1.4
     */
    public function countByAttributes($attributes, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.countByAttributes()', 'system.db.ar.CActiveRecord');
        $prefix = $this->getTableAlias(true) . '.';
        $builder = $this->getCommandBuilder();
        $this->beforeCount();
        $criteria = $builder->createColumnCriteria($this->getTableSchema(), $attributes, $condition, $params, $prefix);
        $this->applyScopes($criteria);

        if (empty($criteria->with))
            return $builder->createCountCommand($this->getTableSchema(), $criteria)->queryScalar();
        else {
            $finder = $this->getActiveFinder($criteria->with);
            return $finder->count($criteria);
        }
    }

    /**
     * Finds the number of rows using the given SQL statement.
     * This is equivalent to calling {@link CDbCommand::queryScalar} with the specified
     * SQL statement and the parameters.
     * @param string $sql the SQL statement
     * @param array $params parameters to be bound to the SQL statement
     * @return string the number of rows using the given SQL statement. Note: type is string to keep max. precision.
     */
    public function countBySql($sql, $params = array())
    {
        Yii::trace(get_class($this) . '.countBySql()', 'system.db.ar.CActiveRecord');
        $this->beforeCount();
        return $this->getCommandBuilder()->createSqlCommand($sql, $params)->queryScalar();
    }

    /**
     * Checks whether there is row satisfying the specified condition.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return boolean whether there is row satisfying the specified condition.
     */
    public function exists($condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.exists()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $criteria = $builder->createCriteria($condition, $params);
        $table = $this->getTableSchema();
        $criteria->select = '1';
        $criteria->limit = 1;
        $this->applyScopes($criteria);

        if (empty($criteria->with))
            return $builder->createFindCommand($table, $criteria, $this->getTableAlias(false, false))->queryRow() !== false;
        else {
            $criteria->select = '*';
            $finder = $this->getActiveFinder($criteria->with);
            return $finder->count($criteria) > 0;
        }
    }

    /**
     * Specifies which related objects should be eagerly loaded.
     * This method takes variable number of parameters. Each parameter specifies
     * the name of a relation or child-relation. For example,
     * <pre>
     * // find all posts together with their author and comments
     * Post::model()->with('author','comments')->findAll();
     * // find all posts together with their author and the author's profile
     * Post::model()->with('author','author.profile')->findAll();
     * </pre>
     * The relations should be declared in {@link relations()}.
     *
     * By default, the options specified in {@link relations()} will be used
     * to do relational query. In order to customize the options on the fly,
     * we should pass an array parameter to the with() method. The array keys
     * are relation names, and the array values are the corresponding query options.
     * For example,
     * <pre>
     * Post::model()->with(array(
     *     'author'=>array('select'=>'id, name'),
     *     'comments'=>array('condition'=>'approved=1', 'order'=>'create_time'),
     * ))->findAll();
     * </pre>
     *
     * @return CActiveRecord the AR object itself.
     */
    public function with()
    {
        if (func_num_args() > 0) {
            $with = func_get_args();
            if (is_array($with[0]))  // the parameter is given as an array
                $with = $with[0];
            if (!empty($with))
                $this->getDbCriteria()->mergeWith(array('with' => $with));
        }
        return $this;
    }

    /**
     * Sets {@link CDbCriteria::together} property to be true.
     * This is only used in relational AR query. Please refer to {@link CDbCriteria::together}
     * for more details.
     * @return CActiveRecord the AR object itself
     * @since 1.1.4
     */
    public function together()
    {
        $this->getDbCriteria()->together = true;
        return $this;
    }

    /**
     * Updates records with the specified primary key(s).
     * See {@link find()} for detailed explanation about $condition and $params.
     * Note, the attributes are not checked for safety and validation is NOT performed.
     * @param mixed $pk primary key value(s). Use array for multiple primary keys. For composite key, each key value must be an array (column name=>column value).
     * @param array $attributes list of attributes (name=>$value) to be updated
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return integer the number of rows being updated
     */
    public function updateByPk($pk, $attributes, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.updateByPk()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $table = $this->getTableSchema();
        $criteria = $builder->createPkCriteria($table, $pk, $condition, $params);
        $command = $builder->createUpdateCommand($table, $attributes, $criteria);
        return $command->execute();
    }

    /**
     * Updates records with the specified condition.
     * See {@link find()} for detailed explanation about $condition and $params.
     * Note, the attributes are not checked for safety and no validation is done.
     * @param array $attributes list of attributes (name=>$value) to be updated
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return integer the number of rows being updated
     */
    public function updateAll($attributes, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.updateAll()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $criteria = $builder->createCriteria($condition, $params);
        $command = $builder->createUpdateCommand($this->getTableSchema(), $attributes, $criteria);
        return $command->execute();
    }

    /**
     * Updates one or several counter columns.
     * Note, this updates all rows of data unless a condition or criteria is specified.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param array $counters the counters to be updated (column name=>increment value)
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return integer the number of rows being updated
     * @see saveCounters
     */
    public function updateCounters($counters, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.updateCounters()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $criteria = $builder->createCriteria($condition, $params);
        $command = $builder->createUpdateCounterCommand($this->getTableSchema(), $counters, $criteria);
        return $command->execute();
    }

    /**
     * Deletes rows with the specified primary key.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param mixed $pk primary key value(s). Use array for multiple primary keys. For composite key, each key value must be an array (column name=>column value).
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return integer the number of rows deleted
     */
    public function deleteByPk($pk, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.deleteByPk()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $criteria = $builder->createPkCriteria($this->getTableSchema(), $pk, $condition, $params);
        $command = $builder->createDeleteCommand($this->getTableSchema(), $criteria);
        return $command->execute();
    }

    /**
     * Deletes rows with the specified condition.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return integer the number of rows deleted
     */
    public function deleteAll($condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.deleteAll()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $criteria = $builder->createCriteria($condition, $params);
        $command = $builder->createDeleteCommand($this->getTableSchema(), $criteria);
        return $command->execute();
    }

    /**
     * Deletes rows which match the specified attribute values.
     * See {@link find()} for detailed explanation about $condition and $params.
     * @param array $attributes list of attribute values (indexed by attribute names) that the active records should match.
     * An attribute value can be an array which will be used to generate an IN condition.
     * @param mixed $condition query condition or criteria.
     * @param array $params parameters to be bound to an SQL statement.
     * @return integer number of rows affected by the execution.
     */
    public function deleteAllByAttributes($attributes, $condition = '', $params = array())
    {
        Yii::trace(get_class($this) . '.deleteAllByAttributes()', 'system.db.ar.CActiveRecord');
        $builder = $this->getCommandBuilder();
        $table = $this->getTableSchema();
        $criteria = $builder->createColumnCriteria($table, $attributes, $condition, $params);
        $command = $builder->createDeleteCommand($table, $criteria);
        return $command->execute();
    }

    /**
     * Creates an active record with the given attributes.
     * This method is internally used by the find methods.
     * @param array $attributes attribute values (column name=>column value)
     * @param boolean $callAfterFind whether to call {@link afterFind} after the record is populated.
     * @return CActiveRecord the newly created active record. The class of the object is the same as the model class.
     * Null is returned if the input data is false.
     */
    public function populateRecord($attributes, $callAfterFind = true)
    {
        if ($attributes !== false) {
            $record = $this->instantiate($attributes);
            $record->setScenario('update');
            $record->init();
            $md = $record->getMetaData();
            foreach ($attributes as $name => $value) {
                if (property_exists($record, $name))
                    $record->$name = $value;
                elseif (isset($md->columns[$name]))
                    $record->_attributes[$name] = $value;
            }
            $record->_pk = $record->getPrimaryKey();
            $record->attachBehaviors($record->behaviors());
            if ($callAfterFind)
                $record->afterFind();
            return $record;
        } else
            return null;
    }

    /**
     * Creates a list of active records based on the input data.
     * This method is internally used by the find methods.
     * @param array $data list of attribute values for the active records.
     * @param boolean $callAfterFind whether to call {@link afterFind} after each record is populated.
     * @param string $index the name of the attribute whose value will be used as indexes of the query result array.
     * If null, it means the array will be indexed by zero-based integers.
     * @return CActiveRecord[] list of active records.
     */
    public function populateRecords($data, $callAfterFind = true, $index = null)
    {
        $records = array();
        foreach ($data as $attributes) {
            if (($record = $this->populateRecord($attributes, $callAfterFind)) !== null) {
                if ($index === null)
                    $records[] = $record;
                else
                    $records[$record->$index] = $record;
            }
        }
        return $records;
    }

    /**
     * Creates an active record instance.
     * This method is called by {@link populateRecord} and {@link populateRecords}.
     * You may override this method if the instance being created
     * depends the attributes that are to be populated to the record.
     * For example, by creating a record based on the value of a column,
     * you may implement the so-called single-table inheritance mapping.
     * @param array $attributes list of attribute values for the active records.
     * @return CActiveRecord the active record
     */
    protected function instantiate($attributes)
    {
        $class = get_class($this);
        $model = new $class(null);
        return $model;
    }

    /**
     * Returns whether there is an element at the specified offset.
     * This method is required by the interface ArrayAccess.
     * @param mixed $offset the offset to check on
     * @return boolean
     */
    public function offsetExists($offset)
    {
        return $this->__isset($offset);
    }

}

/**
 * CBaseActiveRelation is the base class for all active relations.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 */
class CBaseActiveRelation extends CComponent
{

    /**
     * @var string name of the related object
     */
    public $name;

    /**
     * @var string name of the related active record class
     */
    public $className;

    /**
     * @var mixed the foreign key in this relation
     */
    public $foreignKey;

    /**
     * @var mixed list of column names (an array, or a string of names separated by commas) to be selected.
     * Do not quote or prefix the column names unless they are used in an expression.
     * In that case, you should prefix the column names with 'relationName.'.
     */
    public $select = '*';

    /**
     * @var string WHERE clause. For {@link CActiveRelation} descendant classes, column names
     * referenced in the condition should be disambiguated with prefix 'relationName.'.
     */
    public $condition = '';

    /**
     * @var array the parameters that are to be bound to the condition.
     * The keys are parameter placeholder names, and the values are parameter values.
     */
    public $params = array();

    /**
     * @var string GROUP BY clause. For {@link CActiveRelation} descendant classes, column names
     * referenced in this property should be disambiguated with prefix 'relationName.'.
     */
    public $group = '';

    /**
     * @var string how to join with other tables. This refers to the JOIN clause in an SQL statement.
     * For example, <code>'LEFT JOIN users ON users.id=authorID'</code>.
     * @since 1.1.3
     */
    public $join = '';

    /**
     * @var string HAVING clause. For {@link CActiveRelation} descendant classes, column names
     * referenced in this property should be disambiguated with prefix 'relationName.'.
     */
    public $having = '';

    /**
     * @var string ORDER BY clause. For {@link CActiveRelation} descendant classes, column names
     * referenced in this property should be disambiguated with prefix 'relationName.'.
     */
    public $order = '';

    /**
     * Constructor.
     * @param string $name name of the relation
     * @param string $className name of the related active record class
     * @param string $foreignKey foreign key for this relation
     * @param array $options additional options (name=>value). The keys must be the property names of this class.
     */
    public function __construct($name, $className, $foreignKey, $options = array())
    {
        $this->name = $name;
        $this->className = $className;
        $this->foreignKey = $foreignKey;
        foreach ($options as $name => $value)
            $this->$name = $value;
    }

    /**
     * Merges this relation with a criteria specified dynamically.
     * @param array $criteria the dynamically specified criteria
     * @param boolean $fromScope whether the criteria to be merged is from scopes
     */
    public function mergeWith($criteria, $fromScope = false)
    {
        if ($criteria instanceof CDbCriteria)
            $criteria = $criteria->toArray();
        if (isset($criteria['select']) && $this->select !== $criteria['select']) {
            if ($this->select === '*')
                $this->select = $criteria['select'];
            elseif ($criteria['select'] !== '*') {
                $select1 = is_string($this->select) ? preg_split('/\s*,\s*/', trim($this->select), -1, PREG_SPLIT_NO_EMPTY) : $this->select;
                $select2 = is_string($criteria['select']) ? preg_split('/\s*,\s*/', trim($criteria['select']), -1, PREG_SPLIT_NO_EMPTY) : $criteria['select'];
                $this->select = array_merge($select1, array_diff($select2, $select1));
            }
        }

        if (isset($criteria['condition']) && $this->condition !== $criteria['condition']) {
            if ($this->condition === '')
                $this->condition = $criteria['condition'];
            elseif ($criteria['condition'] !== '')
                $this->condition = "({$this->condition}) AND ({$criteria['condition']})";
        }

        if (isset($criteria['params']) && $this->params !== $criteria['params'])
            $this->params = array_merge($this->params, $criteria['params']);

        if (isset($criteria['order']) && $this->order !== $criteria['order']) {
            if ($this->order === '')
                $this->order = $criteria['order'];
            elseif ($criteria['order'] !== '')
                $this->order = $criteria['order'] . ', ' . $this->order;
        }

        if (isset($criteria['group']) && $this->group !== $criteria['group']) {
            if ($this->group === '')
                $this->group = $criteria['group'];
            elseif ($criteria['group'] !== '')
                $this->group.=', ' . $criteria['group'];
        }

        if (isset($criteria['join']) && $this->join !== $criteria['join']) {
            if ($this->join === '')
                $this->join = $criteria['join'];
            elseif ($criteria['join'] !== '')
                $this->join.=' ' . $criteria['join'];
        }

        if (isset($criteria['having']) && $this->having !== $criteria['having']) {
            if ($this->having === '')
                $this->having = $criteria['having'];
            elseif ($criteria['having'] !== '')
                $this->having = "({$this->having}) AND ({$criteria['having']})";
        }
    }

}

/**
 * CStatRelation represents a statistical relational query.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 */
class CStatRelation extends CBaseActiveRelation
{

    /**
     * @var string the statistical expression. Defaults to 'COUNT(*)', meaning
     * the count of child objects.
     */
    public $select = 'COUNT(*)';

    /**
     * @var mixed the default value to be assigned to those records that do not
     * receive a statistical query result. Defaults to 0.
     */
    public $defaultValue = 0;

    /**
     * Merges this relation with a criteria specified dynamically.
     * @param array $criteria the dynamically specified criteria
     * @param boolean $fromScope whether the criteria to be merged is from scopes
     */
    public function mergeWith($criteria, $fromScope = false)
    {
        if ($criteria instanceof CDbCriteria)
            $criteria = $criteria->toArray();
        parent::mergeWith($criteria, $fromScope);

        if (isset($criteria['defaultValue']))
            $this->defaultValue = $criteria['defaultValue'];
    }

}

/**
 * CActiveRelation is the base class for representing active relations that bring back related objects.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 * @since 1.0
 */
class CActiveRelation extends CBaseActiveRelation
{

    /**
     * @var string join type. Defaults to 'LEFT OUTER JOIN'.
     */
    public $joinType = 'LEFT OUTER JOIN';

    /**
     * @var string ON clause. The condition specified here will be appended to the joining condition using AND operator.
     */
    public $on = '';

    /**
     * @var string the alias for the table that this relation refers to. Defaults to null, meaning
     * the alias will be the same as the relation name.
     */
    public $alias;

    /**
     * @var string|array specifies which related objects should be eagerly loaded when this related object is lazily loaded.
     * For more details about this property, see {@link CActiveRecord::with()}.
     */
    public $with = array();

    /**
     * @var boolean whether this table should be joined with the primary table.
     * When setting this property to be false, the table associated with this relation will
     * appear in a separate JOIN statement.
     * If this property is set true, then the corresponding table will ALWAYS be joined together
     * with the primary table, no matter the primary table is limited or not.
     * If this property is not set, the corresponding table will be joined with the primary table
     * only when the primary table is not limited.
     */
    public $together;

    /**
     * @var mixed scopes to apply
     * Can be set to the one of the following:
     * <ul>
     * <li>Single scope: 'scopes'=>'scopeName'.</li>
     * <li>Multiple scopes: 'scopes'=>array('scopeName1','scopeName2').</li>
     * </ul>
     * @since 1.1.9
     */
    public $scopes;

    /**
     * @var string the name of the relation that should be used as the bridge to this relation.
     * Defaults to null, meaning don't use any bridge.
     * @since 1.1.7
     */
    public $through;

    /**
     * Merges this relation with a criteria specified dynamically.
     * @param array $criteria the dynamically specified criteria
     * @param boolean $fromScope whether the criteria to be merged is from scopes
     */
    public function mergeWith($criteria, $fromScope = false)
    {
        if ($criteria instanceof CDbCriteria)
            $criteria = $criteria->toArray();
        if ($fromScope) {
            if (isset($criteria['condition']) && $this->on !== $criteria['condition']) {
                if ($this->on === '')
                    $this->on = $criteria['condition'];
                elseif ($criteria['condition'] !== '')
                    $this->on = "({$this->on}) AND ({$criteria['condition']})";
            }
            unset($criteria['condition']);
        }

        parent::mergeWith($criteria);

        if (isset($criteria['joinType']))
            $this->joinType = $criteria['joinType'];

        if (isset($criteria['on']) && $this->on !== $criteria['on']) {
            if ($this->on === '')
                $this->on = $criteria['on'];
            elseif ($criteria['on'] !== '')
                $this->on = "({$this->on}) AND ({$criteria['on']})";
        }

        if (isset($criteria['with']))
            $this->with = $criteria['with'];

        if (isset($criteria['alias']))
            $this->alias = $criteria['alias'];

        if (isset($criteria['together']))
            $this->together = $criteria['together'];
    }

}

/**
 * CBelongsToRelation represents the parameters specifying a BELONGS_TO relation.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 * @since 1.0
 */
class CBelongsToRelation extends CActiveRelation
{
    
}

/**
 * CHasOneRelation represents the parameters specifying a HAS_ONE relation.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 * @since 1.0
 */
class CHasOneRelation extends CActiveRelation
{
    
}

/**
 * CHasManyRelation represents the parameters specifying a HAS_MANY relation.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 * @since 1.0
 */
class CHasManyRelation extends CActiveRelation
{

    /**
     * @var integer limit of the rows to be selected. It is effective only for lazy loading this related object. Defaults to -1, meaning no limit.
     */
    public $limit = -1;

    /**
     * @var integer offset of the rows to be selected. It is effective only for lazy loading this related object. Defaults to -1, meaning no offset.
     */
    public $offset = -1;

    /**
     * @var string the name of the column that should be used as the key for storing related objects.
     * Defaults to null, meaning using zero-based integer IDs.
     */
    public $index;

    /**
     * Merges this relation with a criteria specified dynamically.
     * @param array $criteria the dynamically specified criteria
     * @param boolean $fromScope whether the criteria to be merged is from scopes
     */
    public function mergeWith($criteria, $fromScope = false)
    {
        if ($criteria instanceof CDbCriteria)
            $criteria = $criteria->toArray();
        parent::mergeWith($criteria, $fromScope);
        if (isset($criteria['limit']) && $criteria['limit'] > 0)
            $this->limit = $criteria['limit'];

        if (isset($criteria['offset']) && $criteria['offset'] >= 0)
            $this->offset = $criteria['offset'];

        if (isset($criteria['index']))
            $this->index = $criteria['index'];
    }

}

/**
 * CManyManyRelation represents the parameters specifying a MANY_MANY relation.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 * @since 1.0
 */
class CManyManyRelation extends CHasManyRelation
{

    /**
     * @var string name of the junction table for the many-to-many relation.
     */
    private $_junctionTableName = null;

    /**
     * @var array list of foreign keys of the junction table for the many-to-many relation.
     */
    private $_junctionForeignKeys = null;

    /**
     * @return string junction table name.
     * @since 1.1.12
     */
    public function getJunctionTableName()
    {
        if ($this->_junctionTableName === null)
            $this->initJunctionData();
        return $this->_junctionTableName;
    }

    /**
     * @return array list of junction table foreign keys.
     * @since 1.1.12
     */
    public function getJunctionForeignKeys()
    {
        if ($this->_junctionForeignKeys === null)
            $this->initJunctionData();
        return $this->_junctionForeignKeys;
    }

    /**
     * Initializes values of {@link junctionTableName} and {@link junctionForeignKeys} parsing
     * {@link foreignKey} value.
     * @throws CDbException if {@link foreignKey} has been specified in wrong format.
     */
    private function initJunctionData()
    {
        if (!preg_match('/^\s*(.*?)\((.*)\)\s*$/', $this->foreignKey, $matches))
            throw new CDbException(Yii::t('yii', 'The relation "{relation}" in active record class "{class}" is specified with an invalid foreign key. The format of the foreign key must be "joinTable(fk1,fk2,...)".', array('{class}' => $this->className, '{relation}' => $this->name)));
        $this->_junctionTableName = $matches[1];
        $this->_junctionForeignKeys = preg_split('/\s*,\s*/', $matches[2], -1, PREG_SPLIT_NO_EMPTY);
    }

}

/**
 * CActiveRecordMetaData represents the meta-data for an Active Record class.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.db.ar
 * @since 1.0
 */
class CActiveRecordMetaData
{

    /**
     * @var CDbTableSchema the table schema information
     */
    public $tableSchema;

    /**
     * @var array table columns
     */
    public $columns;

    /**
     * @var array list of relations
     */
    public $relations = array();

    /**
     * @var array attribute default values
     */
    public $attributeDefaults = array();
    private $_modelClassName;

    /**
     * Constructor.
     * @param CActiveRecord $model the model instance
     * @throws CDbException if specified table for active record class cannot be found in the database
     */
    public function __construct($model)
    {
        $this->_modelClassName = get_class($model);

        $tableName = $model->tableName();
        if (($table = $model->getDbConnection()->getSchema()->getTable($tableName)) === null)
            throw new CDbException(Yii::t('yii', 'The table "{table}" for active record class "{class}" cannot be found in the database.', array('{class}' => $this->_modelClassName, '{table}' => $tableName)));
        if ($table->primaryKey === null) {
            $table->primaryKey = $model->primaryKey();
            if (is_string($table->primaryKey) && isset($table->columns[$table->primaryKey]))
                $table->columns[$table->primaryKey]->isPrimaryKey = true;
            elseif (is_array($table->primaryKey)) {
                foreach ($table->primaryKey as $name) {
                    if (isset($table->columns[$name]))
                        $table->columns[$name]->isPrimaryKey = true;
                }
            }
        }
        $this->tableSchema = $table;
        $this->columns = $table->columns;

        foreach ($table->columns as $name => $column) {
            if (!$column->isPrimaryKey && $column->defaultValue !== null)
                $this->attributeDefaults[$name] = $column->defaultValue;
        }

        foreach ($model->relations() as $name => $config) {
            $this->addRelation($name, $config);
        }
    }

    /**
     * Adds a relation.
     *
     * $config is an array with three elements:
     * relation type, the related active record class and the foreign key.
     *
     * @throws CDbException
     * @param string $name $name Name of the relation.
     * @param array $config $config Relation parameters.
     * @return void
     * @since 1.1.2
     */
    public function addRelation($name, $config)
    {
        if (isset($config[0], $config[1], $config[2]))  // relation class, AR class, FK
            $this->relations[$name] = new $config[0]($name, $config[1], $config[2], array_slice($config, 3));
        else
            throw new CDbException(Yii::t('yii', 'Active record "{class}" has an invalid configuration for relation "{relation}". It must specify the relation type, the related active record class and the foreign key.', array('{class}' => $this->_modelClassName, '{relation}' => $name)));
    }

    /**
     * Checks if there is a relation with specified name defined.
     *
     * @param string $name $name Name of the relation.
     * @return boolean
     * @since 1.1.2
     */
    public function hasRelation($name)
    {
        return isset($this->relations[$name]);
    }

    /**
     * Deletes a relation with specified name.
     *
     * @param string $name $name
     * @return void
     * @since 1.1.2
     */
    public function removeRelation($name)
    {
        unset($this->relations[$name]);
    }

}
